1. Field of the Invention
The present invention relates to an electroacoustic transducer such as a speaker using a diaphragm made of deformable electrostrictive polymer and a method for producing the diaphragm used in the electroacoustic transducer.
2. Description of Related Art
Proposed has been an electroacoustic transducer having a diaphragm and an electrode layers across which an audio signal voltage biased by a direct-current biased voltage is applied, that are placed on a front surface and a rear surface of the diaphragm. The electroacoustic transducer has used a difference in air pressure of the front surface and the rear surface of the diaphragm to form the concave or convex diaphragm so that it can convert any deformation of the diaphragm on its surface direction into any vibration in a thickness direction of the diaphragm, thereby emitting an audio signal. For example, the Japanese Patent Application Publication No. S55-73199 has disclosed the electroacoustic transducer in which a diaphragm made of polyvinylidene fluoride film as piezoelectric polymer has been used. Further, International Application No. PCT/US98/02311 (International Publication No. WO 98/3529) has disclosed a sonic actuator in which a diaphragm made of elastomeric dielectric polymer has been used.